John 1:4 says In Him (Jesus) was life and the life was the light of men. At that time there were some people who used to think that they had life but to my surprise only Jesus had life according to John1:4. Meaning that some someone can say that he is alive, yet he is dead. Thats why Jesus had to say unless a man is born again, he cannot enter the kingdom of God. After our natural birth there is a need of the birth of the spirit. The reason why we say of the spirit is that when man is born again that which is born of flesh is flesh, and that which is born of Spirit is spirit (John3:6). So, we need to be born again. John 10, Jesus said that he came that we might have and might have it in abundance. Now the opposite of life is death, and this death came through sin as the scripture says the wages of sin is death. Meaning the life that Jesus was giving it was to compensate the effect of what men did at the cross. So, Jesus did not come to the world to destroy sin only but the effects of sin as well. He destroyed the works of the devil at the cross. And the scripture says that the last enemy he will destroy is death (1 Corinthians 6:15).